Hardware Abstraction Layer as an SDN-enabler for Non-OpenFlow Network Equipment

This paper describes an experimentally-tested approach towards programmability for legacy network elements in the software-defined networking architecture. As OpenFlow is a leading control-plane protocol enabling SDN in modern networks, yet not all equipment is compatible with this framework. This problem is addressed in ALIEN, the FP7 research project, where Hardware Abstraction Layer (HAL) for non-OpenFlow capable devices is introduced. This paper describes outcomes of the project, and specifically, gives a set of examples of the successful implementation of OpenFlow through the HAL on 'alien' devices.